U.S. Highway 81 (US 81) is a U.S. Highway that begins at an interchange with Interstate 35W/US 287 (I-35W/US 287) in northern Fort Worth in Texas. US 81 leaves the state and crosses the Red River into Oklahoma between Ringgold, Texas, and Terral, Oklahoma.

US 81 begins at an interchange with I-35W/US 287 in northern Fort Worth. The two highways travel northwest as a freeway, passing by the Bureau of Engraving and Printing near Blue Mound Road (Farm to Market Road 156, FM 156), through the city's northwest side. US 81/US 287 leaves the city of Fort Worth and enters Wise County near Avondale. The highway runs through or near the towns of Rhome, New Fairview, Decatur, Alvord, and Sunset before separating in southern Bowie. US 81 runs through the town as Wise Street, running in a more east–west direction before turning in a more north–south direction at FM 174. The highway has a mostly rural route, running through western Montague County, before crossing the Red River into Oklahoma.

US 81 at its inception in 1926 followed the route of State Highway 2 (SH 2), which began in Laredo and passed through San Antonio, Austin, Waco, and Fort Worth before passing over the Red River into Oklahoma four miles (6.4 km) north of Ringgold. The 1936 Official Map of the Highway System of Texas clearly shows the route labeled both as US 81 and SH 2. It was cosigned with US 83 for 18 miles (29 km) from Laredo to 2 miles (3.2 km) south of Webb, with US 79 for 18 miles (29 km) from Austin north to Round Rock, and with US 77 for 33 miles (53 km) from Waco to Hillsboro. In 1940 US 287 was extended south into Texas, and a 67-mile (108 km) stretch from Fort Worth northwest to Bowie was cosigned with US 81. The summer 1941 Texas Highway Map shows this pairing, and the current southern terminus of US 81 is still cosigned with US 287.

The spring and summer 1949 Texas Highway Department Official Map designates the length of US 81 from Laredo to Fort Worth as part of the National System of Interstate Highways, but no numeric designation was given at the time.

It was not until 1959 that parts of US 81 in Texas appeared on the Texas Official Highway Travel Map cosigned with I-35 shields. Succeeding maps reflect the slow completion of I-35 and I-35W over the stretch of US 81 between Laredo and Fort Worth, with the 1978-79 Texas Official Highway Travel Map showing only a 14-mile (23 km) section from Encinal north to 3 miles (4.8 km) south of Artesia Wells as incomplete, and the 1980 Texas Official Highway Travel Map shows that section completed. In 1980, US 81 was cosigned with I-35 and I-35W except where the Interstate bypassed towns; US 81 provided the main route through town and then reconnected with I-35 on the other side. The longest section of US 81 in 1980 not cosigned with the Interstate ran from I-35 in Hillsboro 20 miles (32 km) north to I-35W, just north of Grandview. This section of US 81 became SH 81 in 1991 when most of US 81 in Texas was decommissioned. The section of highway from Devine to Lytle became SH 132 and the section from Derby to the Pearsall town square became Spur 581 when US 81 south of Fort Worth was decommissioned in 1991.

County	Location	mi	km	Destinations	Notes
Tarrant	Fort Worth	0.0	0.0	I-35W south / US 287 south – Fort Worth, Denton	South end of US 287 overlap/freeway; I-35W exit 60
		1.5	2.4	FM 3479 (Harmon Road)
		3.1	5.0	FM 156 (Blue Mound Road) – Blue Mound, Haslet, Bureau of Engraving and Printing
		3.9	6.3	Bonds Ranch Road, Hicks Road
		6.2	10.0	Blue Mound Road West, Willow Springs Road
	Avondale–Fort Worth line	8.2	13.2	Bus. US 287 south / FM 718 – Newark, Saginaw	North end of freeway
Wise	Rhome	14.7	23.7	SH 114 east – Dallas, Texas Motor Speedway, Roanoke	South end of freeway; south end of SH 114 overlap
		15.6	25.1	Bus. US 81 north / Bus. US 287 north / FM 3433 – Newark
		15.9	25.6	SH 114 west to SH 101 – Boyd, Bridgeport, Bowie	North end of SH 114 overlap
		16.8	27.0	Bus. US 81 south / Bus. US 287 south / Pioneer Road	North end of freeway
	New Fairview	19.0	30.6	FM 407 east to FM 2264 north – Justin, Lewisville	Interchange
	Decatur	27.7	44.6	Bus. US 81 north / Bus. US 287 north / FM 2264 south – New Fairview, Decatur	Interchange
		29.6	47.6	FM 730 – Boyd	Interchange
		30.7	49.4	Bus. US 380 / FM 51 – Weatherford, Jacksboro, Gainesville, Denton	Interchange
		31.7	51.0	US 380 – Bridgeport, Jacksboro, Denton	Interchange
		32.2	51.8	FM 1810 west (Old Chico Road) – Chico, Maryetta
	​	33.3	53.6	Bus. US 81 south / Bus. US 287 south – Decatur
	Alvord	40.4	65.0	Bus. US 81 north / Bus. US 287 north – Alvord	South end of freeway; no northbound entrance
		40.9	65.8	Hubbard Street	No southbound entrance
		41.9	67.4	FM 1655 (State Street) to FM 2265 west – Newport, Forestburg
		43.4	69.8	Bus. US 81 south / Bus. US 287 south – Alvord	North end of freeway; southbound exit and northbound entrance
Montague	Sunset	48.5	78.1	Spur 511 / Cemetery Road – Sunset	South end of freeway
		49.7	80.0	SH 101 – Bridgeport, Boyd, Rhome
	​	51.5	82.9	Lawhorn Lane
	​	52.9	85.1	Fruitland Road
	​	54.8	88.2	Wagonseller Road
	Bowie	56.6	91.1	US 287 north / SH 101 south – Wichita Falls, Sunset	North end of US 287 overlap/freeway
		58.5	94.1	FM 1125 (Mills Street)
		58.8	94.6	SH 59 – Newport, Jacksboro, Montague, Saint Jo
		59.3	95.4	FM 174 west / FM 1816 north – Windthorst, Archer City, Belcherville
	Stoneburg	67.2	108.1	FM 1806 west	South end of FM 1806 overlap
		67.7	109.0	FM 1806 east – Montague	North end of FM 1806 overlap
	Ringgold	77.6	124.9	US 82 – Henrietta, Wichita Falls, Gainesville, Sherman	Interchange
		78.4	126.2	Spur 19 south to US 82 west – Henrietta, Wichita Falls
	​	81.5	131.2	US 81 north – Ryan, Duncan	Crosses the Red River into Oklahoma
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       Incomplete access

• Texas State Highway 81
• Texas State Highway 132
• Texas State Highway Spur 581